Discussion on:

Set up Samba to serve as a domain controller

Doesn't play nice with NT4 domain controllers.

The implementation of the protocol on a modern Linux system should work fine with win7, I have 4 win7 machines doing just that at one of my locations.

The problem with old NT4 systems is probably the underlying protocol, just different enough that it's unreliable with win7 clients.

The statement that this hack results in NT4-style services is just that; it's the range of features/functions that resemble the NT4 model. (as Jack points out not similar to AD)

PDC join? I don't have problems using shares, but I could not join Win7 boxes to a NT4 PDC regardless of it being a Microsoft NT4.0 server or the latest Linux/Samba distro. (truth be told it's been about a year since I last visited this issue.)

You need to add following records to registry on Windows 7 client:
HKLM\System\CCS\Services\LanmanWorkstation\Parameters
ADD DWORD -> DomainCompatibilityMode = 1
ADD DWORD -> DNSNameResolutionRequired = 0
Than you will be able to join the domain if you have at least:
Samba 3.4 or later
Samba 3.3.5 or later

pgit & jindrich! (and of course the hard working Samba team...)

test

...they want there college labs back

Wow!

This article is too general and inaccurate. Some directives are obsolete and some will not work on newer samba versions. I miss here also some very important settings regarding rights mapping, rights on share and general configuration. You have all described in samba documentation.
Still if you will use this configuration it will work (it will not work with Windows7, because you need to edit registry, check other chats, I've wrote here how to configure Windows7) ...